The present invention is directed generally to counting apparatus, and more particularly to apparatus for counting a plurality of objects, such as eggs, moving along a predetermined path.
While the present invention is useful over a broad range of applications, the disclosure will be facilitated by specific reference to the problem of counting eggs in a commercial egg-producing operation. Counting devices for this purpose are well known in the art. However, the counting devices heretofore in use have encountered some problems.
Specifically, it has heretofore proven difficult with mechanical counters to reliably count a relatively rapidly moving stream of eggs, as for example along a conveyor belt, when the size of the eggs varies by more than a relatively small amount. In this regard, a mechanical switching device can readily be set to count small eggs, or large eggs, but should a number of small eggs immediately follow a number of relatively large eggs down the conveyor belt, the small eggs tend not to be counted. This is true since a mechanical switch must be reset to its inactive or "off" state intermediate each actuation thereof to its active or "on" state by a passing egg.
In prior art systems, a lever is interposed in the path of travel of the eggs along the conveyor belt and is mechanically coupled to the switch for actuating the switch in response to the passage of each egg thereby. However, it will be seen that this lever must be set relatively high so as to permit the passage of relatively large eggs thereby. However, with the lever set relatively high, somewhat smaller eggs may readily pass thereunder without actuating the lever, thus failing to actuate the switch and hence not being counted. On the other hand, if the lever is set low enough to count relatively small eggs it wil impede the passage of relatively larger eggs which may result in damage to the lever, damage to the eggs or both, requiring costly and time consuming repair or readjustment of the counting apparatus, removal of damaged eggs, etc.
It is known to provide adjustment for such mechanical counters so that the average size egg being processed at a given time will cause actuation thereof. Accuracy is improved somewhat by this method, but still, problems can be encountered with the passage of eggs which are either significantly larger or significantly smaller than this average. The prior art has also attempted the use of photo-cell-based counters, which theoretically can produce a high degree of accuracy. However, the poultry house environment contains excessive airborne dust, dirt, and the like which tend to befoul the photo-cell elements, causing excessive maintenance problems.